refactor out FilerClientAccessor

weed/filer_client/filer_client_accessor.go

@@ -0,0 +1,65 @@
+package filer_client
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/seaweedfs/seaweedfs/weed/filer"
+	"github.com/seaweedfs/seaweedfs/weed/glog"
+	"github.com/seaweedfs/seaweedfs/weed/mq/topic"
+	"github.com/seaweedfs/seaweedfs/weed/pb"
+	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
+	"github.com/seaweedfs/seaweedfs/weed/pb/mq_pb"
+	"google.golang.org/grpc"
+	jsonpb "google.golang.org/protobuf/encoding/protojson"
+)
+
+type FilerClientAccessor struct {
+	GetFiler          func() pb.ServerAddress
+	GetGrpcDialOption func() grpc.DialOption
+}
+
+func (fca *FilerClientAccessor) WithFilerClient(streamingMode bool, fn func(filer_pb.SeaweedFilerClient) error) error {
+	return pb.WithFilerClient(streamingMode, 0, fca.GetFiler(), fca.GetGrpcDialOption(), fn)
+}
+
+func (fca *FilerClientAccessor) SaveTopicConfToFiler(t *mq_pb.Topic, conf *mq_pb.ConfigureTopicResponse) error {
+
+	glog.V(0).Infof("save conf for topic %v to filer", t)
+
+	// save the topic configuration on filer
+	topicDir := fmt.Sprintf("%s/%s/%s", filer.TopicsDir, t.Namespace, t.Name)
+	if err := fca.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
+		var buf bytes.Buffer
+		filer.ProtoToText(&buf, conf)
+		return filer.SaveInsideFiler(client, topicDir, "topic.conf", buf.Bytes())
+	}); err != nil {
+		return fmt.Errorf("save topic to %s: %v", topicDir, err)
+	}
+	return nil
+}
+
+func (fca *FilerClientAccessor) ReadTopicConfFromFiler(t topic.Topic) (conf *mq_pb.ConfigureTopicResponse, err error) {
+
+	glog.V(0).Infof("load conf for topic %v from filer", t)
+
+	topicDir := fmt.Sprintf("%s/%s/%s", filer.TopicsDir, t.Namespace, t.Name)
+	if err = fca.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
+		data, err := filer.ReadInsideFiler(client, topicDir, "topic.conf")
+		if err == filer_pb.ErrNotFound {
+			return err
+		}
+		if err != nil {
+			return fmt.Errorf("read topic.conf of %v: %v", t, err)
+		}
+		// parse into filer conf object
+		conf = &mq_pb.ConfigureTopicResponse{}
+		if err = jsonpb.Unmarshal(data, conf); err != nil {
+			return fmt.Errorf("unmarshal topic %v conf: %v", t, err)
+		}
+		return nil
+	}); err != nil {
+		return nil, err
+	}
+
+	return conf, nil
+}